Feeding device



Aug. 17, 1937.

D. W. HART FEEDING DEVICE Filed larch 9. 1936 2 Sheets-Sheet 1 INVENTOR ,Dudlqyl llflavt BY I I H (S ATTORNEY.

Aug. 17, 1937 D, w HA T 2,090,479

FEEDING DEVICE Filed larch 9, 1936 2 Sheets-Sheet 2 INVENTOR HIS ATTORNEY.

Patented Aug. 17, 1937 UNITED STATES PATENT OFFICE manure nEvrcE Dudley W. Hart, Phillipsburg, N. 1., assig mto Ingersoll-Band Company,- Jersey City, N. 1., a corporation of New Jersey Application March 9, I936, Serial No. 67,752

4 Claims.

This invention relates to rock drills, and more particularly to a feeding device for rock drills.

One object of the invention is toexert a constant feeding pressure on a rock drill for feed- 5 ing it towards the work.

Another object is to prevent the transmission of shocks and jars from the rock drill to the motor employed for feeding the rock drill towards the work. 10 Other objects will be in part obvious 'and in part pointed out hereinafter.

In the drawings accompanying this specification and in which similar reference numerals refer to similar parts, i 15 Figure 1 is a side elevation, partly broken away, of a rock drilling mechanism equipped with a feeding device constructed in accordance with the practice of the invention,

Figure 2 is a transverse view taken through Figure 1 on the line 2-2 showing the driving connection between the motor and the transmission member, I

Figure 3 is an elevation, in section, taken through Figure 2 on the line 3-3, showing the 25 power controlling devices for the motor,

Figure 4 is a view taken through Figure 3 on the line 4-4 showing a detail,

Figure 5 is a view taken through Figure 3 on the line 5-5 showing the main throttle valve in do a neutral position,

Figure 6 shows still another view through the main throttle valve and is taken on the line 6-6 through Figure 3,

Figure 7 is a view taken through Figure 3 on 35 the line '|l showing the control valve in a neutral position,

Figures 8 and 9 are elevations, in section, taken through the main throttle valve and showing said valve in position for maintaining a minimum 40 feeding pressure in the motor, and

Figures 10 and 11 are views similar to Figures 8 and 9 showing the main throttle valve in position for supplying maximum feeding pressure to the motor.

45 Referring more particularly to the drawings,

the invention is shown applied to a drilling mechanism comprising a wheeled mounting 2B having mounted thereon, as by means of a clamppivot 2i, a column 22.

60 The column 22 may be of a well known type having a pair of spaced bars 23 of structural shape of which legs 24 provide guiding surfaces for a saddle 25 carrying a rock drill 26. The saddle 25 is adapted to slide on the legs 24 in 66 order to maintain the rock drill within the cor- .rect actuating position with respect to the drill steel 21.

In accordance with the practice of the present invention the column 22 is provided at its extremities with rollers 28 arranged between the 5 -bars'23. The rollers 28 serve as guides for a chain 30 which is connected with one end to the rearward portion of the saddle 25 and with its other end to aforward portion of the saddle 25.

' On the rearward surface of the column 22 is 10 a casing 3i forming a bearing for a shaft 32 to which is keyed'a sprocket driving wheel 33. The chain 30 is looped over the driving wheel 33, and idler sprockets 34 mounted upon shafts 35 supported by the casing 3| are arranged above and below the sprocket wheel 33 and in off-set relation with respect thereto to maintain the chain 30 in full driving engagement with the sprocket wheel 33.

In the structure shown, the power required for driving the sprocket wheel 33 for raising and lowering the rock drill on the column 22 is supplied by a rotary motor 36, preferably of the multi-cylinder type, and of which only the casing and the shaft 31 are shown. The shaft 31 is in splined engagement with a worm 38 meshing with a worm wheel 39 keyed to the shaft 32 upon which the sprocket wheel 33 is mounted. The worm 38 has a free sliding fit on the shaft 3'! and has trunnions 40 at its ends which extend into the inner races of thrust bearings 4| seated in the casing 3i to serve as bearings for the worm and to absorb the end thrust of the worm and thereby prevent the transmission of thrust to the. motor 36. 5

Preferably, the intermeshing portions of the worm and the worm wheel are of a locking pitch so that the rock drill-will remain safely suspended at any point along the length of the column when the motor is at rest and without the need of additional securing devices to prevent it from falling downwardly along the column and possibly injuring the operator.

The pressure fluid utilized for actuating the motor 36 is conveyed thereto by a supply conduit 42 of which the outlet end is controlled by a hollow main throttle valve 43 of the rotary type having ports 44 and 45 adapted to register with the supply pipe 42 in the limiting positions of the throttle valve 43. The pressure fluid thus entering the throttle valve passes therefrom through a passage 46 leading to a valve chamber 41 containing a rotary control valve 48 whereby the direction of rotation of the motor 36 is determined.

pair of passages 49 and 50 which are selectively connected with the supply passage 45 by the valve 48 for actuating the motor 35 in forwardv or reverse directions. The valves 43 and 4. are interlockingly connected, as by means of toothed intermeshing segments and 52 on the valves,

so that when the main throttle valve 43 is ro- .jars resulting during the operation of drilling tated the valve 45 will also rotate to a controlling position. The pressure fluid admitted into the passages 49 and 50 may be distributed to the motor cylinders bya suitable distributing'valve 53 which may be operated by the motor in a be applied to the rock drill, the throttle valve 43 is provided in its periphery with a gash 54 which opens into the port 44 and is of gradually increasing depth towards said port, and in the throttle valve, as shown more particularly in Figures 3, 6, 9 and 11, is a. port 55 which afl'ords communication between the interior of the throttle valve 43 and an atmospheric exhaust port 56 in the casing containing the throttle valve.

The operationpf the device is as follows: After the rock drill has been retracted to the upper portion of the column 22 and a new working implement inserted into the rock drill the valve 48 is moved into a position in which the port 44 will be in full communication with the supply pipe 42 and the port 55 will be blanked off, the control valve 48, being connected to rotate in response to movement of the throttle valve 43, will then occupy a position to establish communication between the supply passage 45 and the passage 49.

In these positions of the valves the motor will operate, through the devices connecting it with the chain 30, to lower the rock drill and bring the working implement into contact with the work. The rock drill may then be set in operation. Thereafter, in order to apply onlya comparatively light feeding pressure to the rock drill sufficient to maintain it in the correct position with respect to the drill steel, the throttle valve is rotated to a position, as in Figures 8 and 9, in which only a very small area of communication exists between the supply pipe 42 and the port 54.

In the new' position of the throttle valve the port 55 will also,be in communication with the atmospheric port 55. Thus, the pressure admit-- ted into the throttle valve and, therefore, to the motor may be conveniently maintained at a value found to be sufllcient to maintain the lower portion of the chain 30 taut, thereby preventing rebound of the rock drill and gradually advancing it accordingly as the drill steel penetrates the work.

With the chain under constant tension the will be imparted to the lowermost portion of the chain 30 and transmitted thereby to the worm 38. However, owing to the manner in which 7 the worm is connected to the motor shaft and to the provision of t bearings for the ends ofthewormthe kswlllbeimpartedtothe casing instead of to the motor shaft.

- After the drill steel has been driven into the work the valve 48 is moved into position for communicgting the passage 45 with the passage 55. The motor will then operate ,to move the rock drill upwardly along the column and withdraw the drill steelfrom the work.

I claim:

1. In a rock drill feeding device, the combination of a guide member and a rock drill slidable thereon, a flexible member on the guide member connected to the rock drill, a motor for driving the flexible member to actuate the rock drill along the guide member and having a-shaft, and a gear train for transmitting the movement of the motor to the flexible member and of which one gear is slidably interlocked with the shaft to prevent the transmission of vibration fro the rock drill to the motor.

- 2. In a rock drill feeding device, the combination of a guide member and a rock drill slidable thereon, a flexible member on the guide member connected to the rock drill, a motor for driving the flexible member to actuate the rock drill along the guide member and having a shaft, a gear train for transmitting the movement of the motor to the flexible member and of which one gear is slidably interlocked with the shaft to prevent the transmission of vibration from the rock drill to the motor, and thrust bearings to receive the end thrust of the gear on the shaft.

3. In a rock drill feeding device, the combination of a guide member and a rock drill slidable thereon, guide rollers on the guide member, a

flexible member trained over the rollers and being connected to the rock drill, a'driving wheel for the flexible member, a motor for driving the flexible member to actuate the rock drill along the guide member and having a shaft, a driving connection between the motor and the driving -whee1 comprising a worm wheel adapted to rotate with the driving wheel, a worm meshing with the worm wheel and being loosely interlocked with the'motor shaft, and thrust bearings to receive the end thrust of the worm and thereby prevent the transmission of shock from the said motor to exert a constant pull on the chain,

a worm meshing with the worm wheel and being loosely interlocked with the motor shaft, the intermeshing portions of said worm and the worm wheel being of a locking pitch, and thrust bearings to receive the end thrust of the worm and thereby prevent the transmission of shock from the rock drill through the chain to the motor.

-- DUDLEY W. HART. 

